preflight

README

Jetstack Preflight

Preflight is a tool to automatically perform Kubernetes cluster configuration checks using Open Policy Agent (OPA).

This repository hosts the agent part of Preflight. It sends data to the Preflight SaaS platform.

Table of Contents

• Jetstack Preflight
  • Project Background
  • Agent
  • Packages
  • Installation

Project Background

Preflight was originally designed to automate Jetstack's production readiness assessments. These are consulting sessions in which a Jetstack engineer inspects a customer's cluster to suggest improvements and identify configuration issues. The product of this assessment is a report which describes any problems and offers remediation advice.

While these assessments have provided a lot of value to many customers, with a complex system like Kubernetes it's hard to thoroughly check everything. Automating the checks allows them to be more comprehensive and much faster.

The automation also allows the checks to be run repeatedly, meaning they can be deployed in-cluster to provide continuous configuration checking. This enables new interesting use cases as policy compliance audits.

Agent

The Preflight agent uses data gatherers to collect required data from Kubernetes and cloud provider APIs before formatting it as JSON for analysis. Once data has been collected, it is sent to the configured backend.

To run the Agent locally you can run:

preflight agent --agent-config-file ./path/to/agent/config/file.yaml

Or, to build and run a version from master:

go run main.go agent --agent-config-file ./path/to/agent/config/file.yaml

You can find the example agent file here.

You might also want to run a local echo server to monitor requests the agent sends:

go run main.go echo

Packages

Policies for cluster configuration are encoded into Preflight packages. Each package focuses on a different infrastructure component, for example the gke package provides rules for the configuration of a GKE cluster.

Preflight packages are implemented using Open Policy Agent with evaluation taking place in the SaaS backend.

Installation

The following instructions walk through the installation of the Preflight agent to gather data about cluster pods and send them to the backend for analysis.

To complete the secret manifest below, you will need to have a Preflight token.

First create a namespace for the preflight components:

apiVersion: v1
kind: Namespace
metadata:
  name: preflight

Next create a secret like the following, substituting your token:

apiVersion: v1
kind: Secret
metadata:
  name: agent-config
  namespace: preflight
type: Opaque
stringData:
  config.yaml: |
    schedule: "* * * * *"
    token: # enter your token here
    endpoint:
      protocol: https
      host: preflight.jetstack.io
      path: /api/v1/datareadings
    data-gatherers:
    - name: "pods"
      kind: "k8s"
      config:
        resource-type:
          resource: pods
          version: v1

Now create a service account with permissions to read cluster resources:

apiVersion: v1
kind: ServiceAccount
metadata:
  name: agent
  namespace: preflight
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: preflight-agent-cluster-viewer
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  # will be able to view all resources, but not rbac and secrets
  name: view
subjects:
- kind: ServiceAccount
  name: agent
  namespace: preflight

Finally deploy the agent:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: agent
  namespace: preflight
spec:
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: agent
  template:
    metadata:
      labels:
        app.kubernetes.io/name: agent
    spec:
      serviceAccountName: agent
      volumes:
      - name: config
        secret:
          secretName: agent-config
      containers:
      - name: agent
        image: quay.io/jetstack/preflight:7d4fa467258b7592d68fd660f1fd1d42e7332231
        args:
        - "agent"
        - "-c"
        - "/etc/secrets/preflight/agent/config.yaml"
        volumeMounts:
        - name: config
          mountPath: "/etc/secrets/preflight/agent"
          readOnly: true
        resources:
          requests:
            memory: "200Mi"
            cpu: "200m"
          limits:
            memory: "200Mi"
            cpu: "200m"